俯卧位通气联合肺复张对肺内/外源性急性呼吸窘迫综合征犬血流动力学的影响

目的 探讨俯卧位通气联合肺复张(RM)对肺内/外源性急性呼吸窘迫综合征(ARDS)血流动力学的影响.方法 杂种犬48只被随机分为8组,气管内注入盐酸复制肺内源性ARDS(ARDSp)模型,静脉注射油酸复制肺外源性ARDS(ARDSe)模型,两种模型分别应用常规机械通气(A组)、俯卧位通气(B组)、控制性肺膨胀(SI,C组)、俯卧位通气联合SI(D组).观察各组基础状态、模型复制成功0、2和5 h 4个时间点血流动力学参数的变化.结果 ①ARDSp模型:中心静脉压(CVP)在A组、c组成模5 h明显增加;肺动脉楔压(PAWP)在C组、D组成模5 h明显增加;平均肺动脉压(MPAP)在A组、C组、D组成模2 h、5 h明显增加;胸腔内血容量指数(ITBI)在c组成模5 h明显降低;4组血管外肺水指数(EVLWI)在成模0、2和5 h均明显增加;心排血指数(CI)在B组、c组成模2和5 h明显降低,在D组成模2 h明显降低,组内各时间点间比较差异均有统计学意义(P均<0.05).②ARDSe模型:EVLwI在4组成模0、2和5 h均较基础值明显增加;其余心脏前负荷、心功能、后负荷相关参数在各组内差异均无统计学意义(P均>O.05).结论 对于不同原因ARDS,俯卧位通气联合SI较单纯应用俯卧位通气或SI血流动力学影响小,其中对ARDSe血流动力学参数更稳定.

Effects of recruitment maneuvers in prone position for pulmonary or extra-pulmonary acute respiratory distress syndrome on hemodynamics in dog

OBJECTIVE: To evaluate the effect of recruitment maneuvers in prone positioning on hemodynamic in dogs with acute respiratory distress syndrome (ARDS) of pulmonary or extra pulmonary origin. METHODS: Forty-eight mongrel dogs were randomly divided into 8 groups with six dogs in each group. Hydrochloric acid was instilled into trachea to reproduce pulmonary ARDS (ARDSp) and oleic acid was intravenously injected to produce extra-pulmonary ARDS (ARDSe). ARDSp and ARDSe dogs were divided into conventional mechanical ventilation group (group A), prone-position ventilation group (group B), sustained inflation (SI) group (group C) and prone-position ventilation + SI group (group D) respectively. Hemodynamic parameters were monitored before injury and 0, 2 and 5 hours after ARDS was reproduced. RESULTS: (1) In group A and group C, central venous pressure (CVP) increased significantly at 5 hours after ARDSp. Five hours after the establishment of ARDSp, pulmonary arterial wedge pressure (PAWP) increased in group C and group D. Mean pulmonary arterial pressure (MPAP) increased remarkably in group A, group C and group D at 2 hours and 5 hours after onset of ARDSp. In group C, intrathoratic blood volume index (ITBI) decreased at 5 hours after the onset of ARDSp. In all the four groups, extravascular lung water index (EVLWI) increased sharply at 0, 2 and 5 hours after onset of ARDSp. In group B and group C, cardiac index (CI) decreased to a greater extent at 2 and 5 hours after onset of ARDSp. CI decreased at 2 hours after onset of ARDSp in group D with statistically significant difference at different time points (all P<0.05). (2) In all four groups, EVLWI increased sharply at 0, 2 and 5 hours after onset of ARDSe. In ARDSe model, there was no significant difference in other hemodynamic parameters between groups (all P>0.05). CONCLUSION: There are less influence on hemodynamics when SI is performed in prone position, and it is even more significantly so in ARDS dogs.